Titanium single-electron transistor fabricated by electron-beam lithography

A method to fabricate non-superconducting mesoscopic tunnel junctions by oxidation of Ti is presented. The fabrication process uses conventional electron-beam lithography and shadow deposition through an organic resist mask. Superconductivity in Ti is suppressed by performing the deposition under a suitable background pressure. We demonstrate the method by making a single-electron transistor which operated at View the MathML source and had a moderate charge noise of View the MathML source at View the MathML source. Based on non-linearities in the current–voltage characteristics at higher voltages, we deduce the oxide barrier height of approximately View the MathML source. The non-superconducting Ti junctions can be useful in several applications.